* ==== TYPE: ST-IF-DEEP ====
      * FEATURE: IF nested 3+ levels deep
      * STATEMENT: IF (nested)
      * BRANCHES: 6, DECISIONS: 3
       IDENTIFICATION DIVISION.
       PROGRAM-ID. IFDEEP.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       01 WS-X       PIC 9(1) VALUE 1.
       01 WS-Y       PIC 9(1) VALUE 2.
       01 WS-Z       PIC 9(1) VALUE 3.
       PROCEDURE DIVISION.
       MAIN.
           IF WS-X = 1
               IF WS-Y = 2
                   IF WS-Z = 3
                       DISPLAY 'OK: NESTED'
                   ELSE
                       DISPLAY 'ERR: Z'
               ELSE
                   DISPLAY 'ERR: Y'
           ELSE
               DISPLAY 'ERR: X'.
           STOP RUN.